Previous studies in symptomatic populations have found that a negative colonoscopy predicts a reduction in colorectal cancer (CRC) incidence for greater than 20 years. The current study examined the impact of a negative colonoscopy in a screening population in Poland, specifically the effects of a high-quality examination (examination to the cecum, adequate bowel preparation, and performance by an endoscopist with an adenoma detection rate [ADR] >20%).
Overall, 165,887 individuals were followed for up to 17.4 years and found to have reductions in CRC incidence and mortality of 72% and 81%, respectively, compared to the general population. The benefits were similar in men and women and seen in both the proximal and distal colon. Beyond 10 years of follow-up, the overall incidence reduction was 69% and mortality reduction was 73%. Compared with low-quality colonoscopy, high-quality examination was associated with a 2-fold greater reduction in the risk for proximal colon cancer. In multivariate analysis, CRC risk was significantly lower among patients who had high-quality colonoscopy than those who had low-quality colonoscopy.
Pilonis ND, Bugajski M, Wieszczy P, et al. Long-term colorectal cancer incidence and mortality after a single negative screening colonoscopy. Ann Intern Med
2020 May 26. (Epub ahead of print) (https://doi.org/10.7326/m19-2477